1. Field of the Invention
The present invention relates to movement of liquids. More particularly, it relates to the movement of large volumes of liquids across a surface.
2. Background of Related Art
Mechanical windshield wipers have become a standard feature on automobiles long ago. Some windshield wipers even start automatically for a driver, giving drivers little reason to even think about their operation. However, when the rubber for a wiper mechanism dries out, a driver is reminded of their existence through noise and less than optimal clearing.
The mechanical windshield wiper was invented by Mary Anderson in 1903, to which a U.S. Pat. No. 743,801 was awarded in September 1905. The '801 patent used manual power to push a wiper mechanism across a windshield to clear rainwater.
The current state of the art for windshield wiper technology relies on electric motors. However, the basic mechanism for pushing a wiper mechanism across a windshield to clear rainwater has changed very little since 1903. Conventional windshield wiper technology has its drawbacks including, e.g., clearing of less than a total windshield area, reliance on a wiper blade that is subject to deterioration, noise, etc.
In recent years, droplets of water and other small amounts of fluids have been moved by an electric field via electrode type devices using common PC board and semiconductor technology. Commonly referred to as microfluidics, the objective has been to manipulate individual droplets (microliter and nanoliter volumes). Key application areas have been biochips, DNA microarrays, continuous-flow microfluidics, including mechanical micropumps and other biochemical analyses. Another application is digital droplet based microfluidics, including electrowetting-on-dielectric (EWOD). All these applications of moving a fluid with an electric field are aimed at manipulating very small droplet volumes of fluid.